Tool-holder for lathes.



M. G. BERSTED;

TOOL HOLDER FOR LATHES. APPLICATION FILED NOV. 17,1913.

1,109,031. Patented Sept. 1, 1914.

THE NORRIS PETERS 60., PHOTO-LITHQ, WASHINGTON. D C.

the work againstthe tool cannot possibly: serve to loosen it, but rather tends to Fig. 2'is atop plan view of the same, with {part thereof in section onthe line BB of Cylinder; and Fig. 7 is'a perspective view of MARTIN o. nn nsrrnn, or CHICAGO, ILLINOIS.

rooanowm' For; LA Hns.

To all whom it may concern: I i

Be it known thatlyM'An'rm C. BERsTn a'citiZen of the United 'States, and resident ofChicago, in thecountyof'Cookand State of Illinois, have invented certain' new and useful Improvements in, Tool 'Holders for Lathes, of which the following a full,

clear, and exact specification. I

My invention 'is cOncJerned. with] cutting tools for lathes,and isfdesigned to produce such a tool that can beground in any desired manner for any kind of cutting, and:

that can be quickly and securelyfastened in narrow bar by asingle movement of a wrenchin such a manner that the thrust of tighten it. 7 I

'To illustrate my invention, I annex hereto a9 sheet'of drawings,in which the same'refl erence characters are used to designateiden tical parts in allthefigures, of which.

Figure 1 is a side elevation ofia tool holder einbodylng myf nventlon, a portion thereof belng 1n sectlonf'bn the line A A'of Fig. 2;

Fig. 1; FigJ3 is a detail in section on the 'lineCC of F 1; Fig. 4 is a central sec- 30 '1 line DD ofFig. 5; Fig.5 is a side elevation through the" locking cylinder, on the 1 tion of the locking cylinder,it and Fig. 4c

connection with the tool.

being on a larger'scale than the remaining figures; Fig. 6 1s-a View slmilar to Fig. l, but showlngqthe tool-located below the locking thepreferred form of wrench which I use in The bar a is of the proper size and shape to be secured in thecustomary manner in the post of the slide-rest, andhas extending di agonally therethrough a slot b which is preferably square in-its shortest cross-seetion provided the cutting tool cjhas, the same cross-section, which is the preferred form. This slot 7) may be located above the locking cylinder d, as seen in Fig. 1, or below it, as seen 'inFig. 6, just as is preferred. The slot b has its vertical sides parallel to the sidesof the bar, so that thetool owill likewise have its sides vertical. This arrangement enables me to grind-the tool to any desired kind of a point or shape that may be necessaryin doing any kind of cutting that lathe or similar work callsfor.

The locking cylinder d is snugly mounted I Specification ofLetters Ifatent. jpgit t d s pt; 1,1914 Application filedii'oveinber 17,1913. ':Seria1"No. 801,334.

"in acylindricalrecess ebored into theside Or ille .end of the bar, which 'rnay beslightly widened forthis purpose, if desired, and the cylinder isheld place so that it is free to rotate by the .rivet f extjendingthrough an aperture in the bottom of the cylinder and riveted in place in the bar in a manner which p will 'be readily apparent in Figs. "2 i i v which is in the form of a regulla'rpolygon,

The cylinder (Z has formed thereina recess g,

preferably a hexagonincross section, as

best'seen in Fig. 4, and adapted to receive the hexagonal headjh of thewren'ch which is used to turn the cylindertolock the tool in position. 'Thelocking cylinder "is; set

flushiinthe bar a, so that-there isnothing to preventthe tool being conveniently brought into "il'n'mediate proximity-to: anysort of work that may benecessary. The locking cylinder d," as best seen in Figs. 4 and5, is

provided with achannel k onitsperiphery,

and this channel has in the bottom thereofa fiat surface Z, which is in position to permit i the tool being slid freely into the I recess Z) when the tool is to'be inserted or withdrawn;

This flat surface engagesthe tool when it is unlocked and preventsthecylinder being turned farther than the proper unlocking position, and it also serves the purpose in the locking'operatio n of compelling the: wor

man to turn the Wrench'inth'e right direction I i to clampthe tool. From this flatportion Z of the bottom offthe channel 7c, the bottom is then curved ;on aconstantlyincreasing radiusuntil the channel merges in'the regular periphery/10f the locking cylinder. This forms a cam surface,sothat when-the cylinder isturned by the wrench after the tool is inserted, the toolis' secu'rely clamped against the opposed face of the recess I), which opx posed face would bethe top side of therecess in the form shownin Fig. 1 and the bot; tom side .in the form shown in Fig. 6. His, however, desirable to clamp the tool notonly ljustimentioned,but also against vone of the adjacent sides, so as to prevent any possible displacement of the tool; laterally; and ,to I

,secure-this result,Iform on one of the sides m of the channel 72 a secondcam surface, which is formed by, placing the channel slightly diagonally, as it'were, of the sur- I l face of, the cylinder. .When the cylinder is I turned tolock the tool, the cam side m of the'channel simultaneously forces the tool against ones-ide of the aperture 6, which side 100 against the opposed face of the 'aperture-b V is at right angles to the opposed side against which it is forced by the cam formed by'the'f 1 and a locking cylinder journaled 1n the bar having an aperture therein polygonal in its bottom of the channel 70;

, The operation of my improved tool holder will be readily apparent. When the tool is inserted inthe bar a, the locking cylinder is in the position shown in Figs. 1, i and 6,

and the wrench j has its head it insertedin I the aperture 9. The wrench is then turned in'the onlydirection possible, which move-y lnent serves toz-rotate the cylindercto locking position, and it will be noted that'the incline to the bottom of the, channel is is so located in all forms that the thrust of the work against the cuttingend, of the tool a which tends to rotate the locking cylinder simply serves to rotate it in the direction which causes it to lock, and thus the'harder the thrust ofthe work on the tool, the more securely the same is locked.

I What I claim as new, and desire to secure by Letters Patent of the United States, is: 1. In a device ofthe class described, the combination with a-holding bar having a 1 diagonalpassage therethrough of a, shape to accommodatea cutting tool having the body thereof rectangularin its shortest cross section, averticalside of the passage being parallel to the vertical sides of the bar, of a tool rectangular in its shortest cross section extending through the passage, and a locking cylinder journaled'in the bar adapted to be turned therein by extraneous means and having some of its cylindrical surface projecting, into thepassage and adapted to engage the tool, said cylinder having a channel therem wider than the ad acent side of the tool forming two cam surfaces thereon,

the cam surface formed by the bottom of the channel which gradually increases in depth cooperating with one sideof the tool, while the second cam surface is formed on one side of" the channel, both cam surfaces lying so that the thrust of the work on the cutting tool tends to rotate the cylinder to tighten its grip on the two sides of the tool engaged by it and to jam its opposite sides against the opposed walls of the passage.

'2. In a. device of the class described, the combination with a holding-bar having a diagonal passage therethr'ough of a shape to'accommodate a cutting tool havingthe body; thereof rectangular in its shortest crossv section, a vertical side-of the passage being parallel to the vertical-sides of the bar, of .a tool rectangular in its shortest cross s'ectlon extending through the passage,

cross section'and adapted to be turned in the bar by a tool cooperating with the aperture and having some of its cylindrical surface projecting into the passage and adapted to engage the tool, said cylinder having a channel therein wider than the adjacent side of the tool and forming two, cam surfaces thereon, the cam surface formed by thebottom- 0f the channel which gradually increases in depth cooperating with one side ofthe tool, while the second cam surface is formed on one side of the channel, bothcam surfaces lying so thatthe thrust, of the work on the cutting'tool tends to rotate the cylinder to tighten its grip on the two sides of the tool engagedbyit and to'jam its oppoe site sides against the opposed walls of the passage. 1 I f a v 3. In a device of the class described, the combination with a holding bar having a diagonal passage therethrough of ashape to accommodate, a cutting tool extending therethrough and having the body thereof rectane gular initsshortest cross section, a vertical side of the passage being parallel to the ver-.

tical sides of the bar, of, a locking cylinder journaled in the bar, adapted to be turned therein by extraneous means, and having some of ltS, cylindrical surface pro ecting intothe passage and adaptedtoengage the tool, said cylinder having a channel therein wider than the adjacent side of the tool and forming two cam surfaces thereon, the cam surface formed by the bottom of the channel, which gradually increases in depth, ca

operating with oneside ofthe tool, while the second cam surface is formed on one side of the channel, both cam surfaces lying so that the thrust of the work on the cutting tool tends to rotate the cylinder to tighten its grip on the two sides of the tool engaged by it andto .jam its opposite sidesagainst the opposed walls of the passage. 1

In witness whereof, I have hereunto set my hand and affixed my seal, this 15th day of November, D. 1918.

v U U MARTITIN OBEBSIED. [11. a] ,Witnessesr J on-nllowAnn MILDRED Ensnnn; 7 7;:

MoELnoY, i

Copies of. this patent maj be obtained for five cents each, itans-55m the Commissioner-oi Eatents, 

